摘要
试验钢在１０５０℃加热及冷却后，主要碳化物相是Ｍ２３Ｃ６、Ｍ７Ｃ３和少量的ＳｉＣ，Ｍ２３Ｃ６和Ｍ７Ｃ３中含有一定的硫。在８７０℃加热时，大块Ｍ２３Ｃ６一般不会聚集长大，粒状Ｍ２３Ｃ６的数量随着保温时间的增加而增多，冷却时在块状Ｍ２３Ｃ６之间还析出相当数量的精细颗粒和薄片Ｍ７Ｃ３，冷却速度愈慢，精细颗粒愈大和薄片愈多。这些遍布在断口面上的精细颗粒、薄片以及大尺寸块状碳化物使试验钢遭到严重弱化。利用热处理手段来改善碳化物的析出特征，大幅度降低其脆化效果还较为困难。推荐这种钢在冷拉前后的软化工艺可采取８７０℃×６ｈ。
After forging,heating at 1050 then cooling,the main phases of carbides in sample steel are M23C6,M7C3 and trace SiC.Some sulphur also exists in M23C6 and M7C3.Heating at 870,large blocky M23C6 usually does not grow up,but the quantity of granular M23C6 increases with extending of soaking time.When cooling,considerable quantity of fine grain and tabular M7C3 is preciptated among blocks of M23C6,and the slower of cooling speed,the lager and more the fine grain and tabular M7C3.These suffusive fine grain and tabular carbides and big size blocky carbides on the face of fracture seriously weaken the sample steel.It is very difficult by heat treatment to improve the precipitation character of carbide and reduce their brittle effect.Before cold drawing,softening process at 8706h water cooling is recommended.
出处
《金属热处理》
CAS
CSCD
北大核心
1999年第8期23-25,共3页
Heat Treatment of Metals
关键词
马氏体钢
碳化物
热处理
阀门钢
柴油机
进气阀
martensitic stainless steel 8Cr20Si2Ni,heat treatment,carbide,weaken
